<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>游戏房间</title>
    <link rel="stylesheet" href="css/common.css">
    <link rel="stylesheet" href="css/game_room.css">
</head>
<body>
    <div class="nav">网络五子棋对战游戏</div>
    <div class="container">
        <div id="chess_area">
            <!-- 棋盘区域, 需要基于 canvas 进行实现 -->
            <canvas id="chess" width="450px" height="450px"></canvas>
            <!-- 显示区域 -->
            <div id="screen"> 等待玩家连接中... </div>
        </div>
        <div id="chat_area" width="400px" height="300px">
            <div id="chat_show">
                <p id="self_msg">你好！</p></br>
                <p id="peer_msg">你好！</p></br>
            </div>
            <div id="msg_show">
                <input type="text" id="chat_input">
                <button id="chat_button">发送</button>
            </div>
        </div>
    </div>
    <script>
        let chessBoard = [];
        let BOARD_ROW_AND_COL = 15;
        let chess = document.getElementById('chess');
        //获取chess控件区域2d画布
        let context = chess.getContext('2d');

        var ws_url = "ws://" + location.host + "/room";
        var ws_hdl = new WebSocket(ws_url);

        var room_info = null;   //用于存储房间的信息
        var now_is_me;  //当前到谁走棋
        var now_is_white;   //当前棋子是否是白色
        var game_over = false;

        function initGame() {
            initBoard();
            // 背景图片
            let logo = new Image();
            logo.src = "image/bj1.webp";
            logo.onload = function () {
                // 绘制图片
                context.drawImage(logo, 0, 0, 450, 450);
                // 绘制棋盘
                drawChessBoard();
            }
        }
        function initBoard() {
            for (let i = 0; i < BOARD_ROW_AND_COL; i++) {
                chessBoard[i] = [];
                for (let j = 0; j < BOARD_ROW_AND_COL; j++) {
                    chessBoard[i][j] = 0;
                }
            }
        }
        // 绘制棋盘网格线
        function drawChessBoard() {
            context.strokeStyle = "#BFBFBF";
            for (let i = 0; i < BOARD_ROW_AND_COL; i++) {
                //横向的线条
                context.moveTo(15 + i * 30, 15);
                context.lineTo(15 + i * 30, 430); 
                context.stroke();
                //纵向的线条
                context.moveTo(15, 15 + i * 30);
                context.lineTo(435, 15 + i * 30); 
                context.stroke();
            }
        }
        //绘制棋子
        function oneStep(i, j, isWhite) {
            if (i < 0 || j < 0) return;
            context.beginPath();
            context.arc(15 + i * 30, 15 + j * 30, 13, 0, 2 * Math.PI);
            context.closePath();
            //createLinearGradient() 方法创建放射状/圆形渐变对象
            var gradient = context.createRadialGradient(15 + i * 30 + 2, 15 + j * 30 - 2, 13, 15 + i * 30 + 2, 15 + j * 30 - 2, 0);
            // 区分黑白子
            if (!isWhite) {
                gradient.addColorStop(0, "#0A0A0A");
                gradient.addColorStop(1, "#636766");
            } else {
                gradient.addColorStop(0, "#D1D1D1");
                gradient.addColorStop(1, "#F9F9F9");
            }
            context.fillStyle = gradient;
            context.fill();
        }
        //棋盘区域的点击事件
        chess.onclick = function (e) {
            //游戏结束后就不能再触发点击事件了
            if(game_over)
            {
                alert("游戏已经结束，请返回大厅");
                return;
            }
            //获取下棋位置，判断当前下棋操作是否正常->是否轮到自己下棋，当前位置有没有棋子
            if(!now_is_me)
            {
                alert("等待对方走棋...");
                return;
            }
            
            let x = e.offsetX;
            let y = e.offsetY;
            // 注意, 横坐标是列, 纵坐标是行
            // 这里是为了让点击操作能够对应到网格线上
            let col = Math.floor(x / 30);
            let row = Math.floor(y / 30);
            if (chessBoard[row][col] != 0) {
                alert("当前位置已有棋子！");
                return;
            }
            // 向服务器发送走棋请求,收到响应后，绘制棋子
            chess_send(row, col);
            // oneStep(col, row, true);    
        }
       function chess_send(r, c)
       {
            var chess_info = {
                optype: "put_chess",
                room_id: room_info.room_id,
                uid: room_info.uid,
                row: r,
                col: c
            }
            ws_hdl.send(JSON.stringify(chess_info));
       }

         
        window.onbeforeunload = function() 
        {
            ws_hdl.close();
        }
        ws_hdl.onopen = function()
        {
            console.log("游戏房间长连接建立成功");
        }
        ws_hdl.onclose = function()
        {
            console.log("游戏房间长连接断开");
        }
        ws_hdl.onerror = function()
        {
            console.log("游戏房间长连接错误");
        }
        function set_screen(me)
        {
            var screen_div = document.getElementById("screen");
            if(me)
                { screen_div.innerHTML = "轮到己方走棋..."; }
            else
                { screen_div.innerHTML = "轮到对方走棋..."; }
        }
        ws_hdl.onmessage = function(evt)
        {
            // 1. 收到room_ready之后进行房间的初始化
            // 1.1将房间信息保存起来
            var info = JSON.parse(evt.data);
            console.log(JSON.stringify(info));
            if(info.optype == "room_ready")// 1.2 初始化显示信息
            {
                room_info = info;
                now_is_me = room_info.uid == room_info.white_id ? true : false;
                set_screen(now_is_me);
                initGame();
            }
            else if(info.optype == "put_chess")
            { 
                // 2. 走棋操作收到走棋请求，绘制棋子
                if(info.result == false)
                {
                    alert(info.reason);
                    return;
                }
                // 当前用户是否是走棋用户，是则走棋，不是则等待
                now_is_me = info.uid == room_info.uid ? false:true;
                // 当前走棋颜色
                now_is_white = info.uid == room_info.white_id? true:false;
                set_screen(now_is_me);
                // 棋子位置符合要求才能下棋
                if(info.row != -1 && info.col != -1)
                {
                    // 绘制棋子
                    oneStep(info.col, info.row, now_is_white); 
                    // 设置棋盘信息
                    chessBoard[info.row][info.col] = 1;
                }
                
                // 是否有胜利者
                if(info.winner == 0)
                    { return; }
                // 胜利了之后，显示胜利信息，添加返回大厅按钮
                game_over = true;   //游戏结束
                var screen_div = document.getElementById("screen");
                if(room_info.uid == info.winner) //打印游戏结束情况
                    { screen_div.innerHTML = info.reason; }
                else
                    { screen_div.innerHTML = "游戏结束，惜败"; }
                
                // 给页面添加按钮用于返回游戏大厅
                var chess_area_div = document.getElementById("chess_area");
                var button_div = document.createElement("div");
                button_div.innerHTML = "返回大厅";
                button_div.onclick = function()
                    { location.replace("/game_hall.html"); }
                chess_area_div.appendChild(button_div);
            }
            // 3. 聊天操作
            else if(info.optype == "chat")
            {   
                if(info.result == false)
                {
                    if(info.uid == room_info.uid)
                    {
                        alert(info.reason);
                        document.getElementById("chat_input").value = "";
                    }
                    return;
                }
                var msg_div = document.createElement("p");
                msg_div.innerHTML = info.message;   
                if(info.uid == room_info.uid)   //js控件
                    { msg_div.setAttribute("id", "self_msg"); }
                else
                    { msg_div.setAttribute("id", "peer_msg"); }

                var br_div = document.createElement("br");
                var msg_show_div = document.getElementById("chat_show");
                msg_show_div.appendChild(msg_div);
                msg_show_div.appendChild(br_div);
                document.getElementById("chat_input").value = "";
            }
            
        }
        // 给发送按钮添加点击事件，获取聊天输入框中的内容，发送给服务器
        var chatbt_div = document.getElementById("chat_button");
        chatbt_div.onclick = function()
        {
            var send_msg = 
            {
                optype: "chat",
                room_id: room_info.room_id,
                uid: room_info.uid,
                message: document.getElementById("chat_input").value
            };
            ws_hdl.send(JSON.stringify(send_msg));
        }
    </script>
</body>
</html>